Reveals Five Commonly Misdiagnosed Vehicle Symptoms and Repairs

Understanding Basic Vehicle Symptoms Can Help Save You $$$, Time - and Maybe Even Avoid an Accident...

Carson, CA – August 4, 2010 – With so many things that can go wrong with today's complex vehicles and, until now, so little information readily available, car owners often find themselves playing a guessing game with symptoms before they reach the repair shop (and even after they've received the official diagnosis). With this in mind,'s ( team of expert mechanics has released a list of five Commonly Misdiagnosed Vehicle Symptoms to help car owners understand that sometimes a squeak is just a squeak -- and sometimes it can mean a lot more.

But, how can you be sure what's really wrong?

Unless you're a certified mechanic or a truly expert DIYer, you can't; but, by doing your homework online, you can narrow down the possibilities and save yourself time and frustration. For example, when a vehicle pulls to one side, some car owners might rush in to get a wheel alignment... when perhaps all that is needed is to inflate the tires to the proper pressure. On the other hand, car owners who put off going to the repair shop might ignore a squeaking noise for weeks, but that symptom could lead to a more expensive repair down the road -- or even impact vehicle handling.

And while it is easy to take for granted that the first and/or cheapest diagnosis is the right one, some vehicle symptoms are indicative of multiple issues, which can lead to frequent misdiagnoses. Bottom line: it is important to make sure you get the right diagnosis so you don't end up paying for an unnecessary, or incorrect repair, which could lead to more trips to your mechanic, and more money out of your pocket.

"Most car owners are simply not going to diagnose (or repair) their vehicles themselves, but what most want is information and peace of mind, which is why helps consumers narrow down their vehicle's symptoms by what they hear, feel, see, or smell," said President Shane Evangelist. "By empowering car owners with easy online access to what might be causing a vehicle's symptoms, not only seeks to help car owners avoid potentially serious safety issues, but also to help them save significant money at the dealership or repair shop."'s Five Commonly Misdiagnosed Symptoms

Common misdiagnosed symptoms, and the corresponding repairs that can be made in error, according to Please note that while these vehicle symptoms are frequently misdiagnosed, any of these diagnoses could be correct. Always consult a certified automotive mechanic before making important automotive repair decisions.

  1. Symptom: Vehicle Pulls to One Side
    • Common Misdiagnosis: The vehicle is out of alignment
    • Repair: Perform a wheel alignment
    • Alternative Diagnosis: The tire pressure is low on one side or the tire has a slipped belt
    • Repair: Inflate the tire, repair a deflated tire, or rotate the tires
    • Comment: Sometimes when a vehicle pulls to one side, the simple 'fix' of inflating your tires will correct the problem as a low or deflated tire(s) can impact vehicle handling. Occasionally, a slipped belt on a tire (which is part of a tire's construction) could be the culprit, and rotating the tires can resolve the issue. Always have your tires inspected for both pressure and wear before you pay for a wheel alignment. An alignment may ultimately be necessary, and one important clue is unevenly worn tires. In all instances, if the vehicle's handling continues to be affected, have it inspected as soon as possible.
  2. Symptom: Engine Will Not Start (Engine Turns Over Slowly or Not at All)
    • Common Misdiagnosis: The battery is bad/dead
    • Repair: Replace the battery
    • Alternative Diagnosis: The alternator is not charging the battery
    • Repair: Replace the alternator and charge the battery
    • Comment: The alternator supplies electrical power to run your car and it charges the car's battery, very similar to the power supply for your laptop computer. Even if the alternator is not charging, the engine will still start once you replace the battery, but the "no start" symptom will return when the new battery becomes discharged. In this case, the battery isn't dead, it's simply discharged. Charging the battery and performing a load test would confirm whether the problem is the battery or just the alternator. The average life expectancy of a battery is three to five years so, if the battery is over three years old, replacing it along with the alternator may be recommended.
  3. Symptom: Clunking or Squeaking Noise When Driving Over Bumps
    • Common Misdiagnosis: The front struts or shock absorbers are worn
    • Repair: Replace the front struts
    • Alternative Diagnosis: The stabilizer bar end links are worn
    • Repair: Replace the end links
    • Comment: A clunking or squeaking noise while driving could be caused by worn shock absorbers or struts (a strut is a combination of a shock absorber and coil spring), but it could also come from worn stabilizer bar end links or ball joints. It can be especially difficult to diagnose a squeaking or clunking noise as several components can cause the same symptom. Always confirm where the sound is coming from before you start replacing parts. If the wrong part is replaced, you will still be driving around with a squeaking/clunking noise, leading to more frustration, more trips to the shop, and more money out of your pocket.
  4. Symptom: Air Conditioning Not Cold Enough
    • Common Misdiagnosis: The refrigerant is low
    • Repair: Recharge the system with refrigerant
    • Alternative Diagnosis: The A/C system has a refrigerant leak
    • Repair: Repair the leak, evacuate and charge the system -- (environmental regulations mandate that this must be done by a trained and certified technician)
    • Comment: recommends that car owners always have a certified technician diagnose and repair the A/C system. If the A/C system has a leak, and a car owner or non-certified mechanic attempts to resolve the issue by adding refrigerant, which is a cooling agent, this will contribute to harmful environmental emissions. To determine if the A/C system actually needs refrigerant, your mechanic should attach high and low pressure gauges. Charging the system, which means adding refrigerant to your vehicle's A/C system, without using pressure gauges could result in an overcharged system. Overcharging even just a little can decrease A/C performance and possibly damage the compressor.
  5. Symptom: Check Engine Light On (With an Oxygen Sensor Code)
    • Common Misdiagnosis: The oxygen sensor is bad
    • Repair: Replace the oxygen sensor
    • Alternative Diagnosis: The engine has a vacuum leak
    • Repair: Replace the leaking vacuum hose
    • Comment: The 'check engine' light illuminates when the vehicle's computer (PCM) detects a malfunction in one or more of the systems that it monitors. A universal code reader or scanner device is used by mechanics to retrieve the diagnostic trouble code, or DTC, which helps indicate the source of the problem. But, the diagnostic trouble code is only the starting point: to rely upon it as the diagnosis, could lead to a misdiagnosis and incorrect part replacement. For example, an oxygen sensor code could be caused by a faulty oxygen sensor or an engine vacuum leak that affects the operation of the oxygen sensor. In that case the vacuum hose needs to be replaced, not the sensor.

To narrow down the possible causes of your vehicle's symptoms, use's free Diagnostic Tools at To find and read reviews of local repair shops, service centers, and dealerships, check out's shopfinder at